Adamawa state police spokesman Mohammed Ibrahim said Thursday that the attackers used sophisticated equipment, including rocket-propelled grenades and improvised explosive devices, to overpower police in Wednesday’s attack. He said that no civilian casualties were reported.

Residents said they were surprised by the attack that came as the area was under a state of emergency. They said that the attackers started shooting to scare people as they engaged the policemen on duty.

Police said the gunmen escaped. The attack comes as northern Nigeria faces attacks by Islamic extremists.